multifuel insert fire

begbeer

At the moment we have an open fire but with an electric insert fire in it. We would like to purchase a multifuel insert fire to go in instead, the problem is the size of our fireplace, it has a wooden surround with marble inserts, the gap from the edge of the opening to each wooden upright is 10 inches only, and from what I have read you need 18inches each side for a free standing model but does it also apply to an insert one. as seems silly we can light an open fire in the grate with the same measurements